In the 1850's, adulteration of beer by publicans was just as prevalent, or so it seems from this article.
"Porter And Stout, And Their Adulterations.
The following are the conclusions arrived at from the analyses instituted of samples of London Stout and Porter obtained from the taps of the several London porter-brewers, and from publicans : —
That the samples of Stout either obtained from agents, or purchased at the taps of several of the principal London porter-brewers, were considerably stronger than those procured from publicans: the alcohol, of specific gravity .796, temperature 60° Fahr., contained in the former samples, ranged from 7.15 per cent, the highest, to 4.53 the lowest; whereas that of the stouts procured from publicans varied, with one exception, from 4.87 per cent, to 3.25 per cent.
That the same difference of strength also characterised the various samples of Porter procured from the two different sources ; the amount of alcohol in the porters obtained from the taps varying from 4.51 per cent, to 2.42 per cent. ; whereas those purchased of publicans ranged from 3.97 per cent, to 1.81 per cent.
That in nearly all the stouts and porters salt was present, often in considerable amount.
That in some of the samples cane-sugar and treacle were likewise present.
There is reason to believe that the variation of strength would have been still more considerable had the samples been procured direct from the several breweries, instead of, as in most cases, from the brewers' taps.
This diminution of strength in the beer purchased of publicans is only to be satisfactorily explained by the addition in many cases of water, this addition being no doubt sometimes practised by the publicans and other retailers of malt liquors.
The addition of water constitutes the principal, but not the only, adulteration to which these beverages are subjected.
Thus the addition of water reduces the strength, flavour, and colour, to such an extent as to necessitate in some cases the further adulteration of the beer, and this is usually effected by means of a very coarse description of brown sugar, containing much treacle, and known as Foots, and salt.
Since the use of cane-sugar is permitted in the brewery, we did not attempt to ascertain which of the samples subjected to analysis contained that substance, because, had we found it in any of the samples, we should still have been unable to have declared whether the brewers or the publicans were the parties who made use of it. We believe, however, that the brewers do not often employ sugar, since it is alleged that beer made with any considerable proportion of cane-sugar does not keep so well as that prepared from malt only. Moreover, the price of sugar forms an obstacle to its use in breweries.
It appears, from the analyses, that salt is almost constantly present in porter. This addition we know is made in the first instance by the brewers themselves; but there is also no doubt that a further quantity of it is frequently used by the publican to assist in bringing up the flavour of beer which has been reduced in strength by the addition of water. The quantity of salt contained in porter is often sufficiently large to communicate a perceptibly saline taste to the mouth. The salt is used by the brewers in the following manner : — It is first mixed up in a tub with flour, usually wheat-flour, and the mixture is cast by handfuls over the surface of the wort in the cooling vat It is said to assist in the preservation and fining of the wort, and it is alleged that these are the only purposes for which it is employed by the brewer.
The three usual and principal adulterations of porter consist, then, of water, by which its strength is reduced and its bulk increased, and sugar and salt, whereby its colour and flavour are in a measure restored. But there is good reason for believing, from evidence given before a recent Committee of the House of Commons on Public Houses, of which Mr. Villiers was the chairman, that other adulterations are practised, and that sulphuric acid, or oil of vitriol, salt of steel. or sulphate of iron, and cocculus indicus, are likewise not unfrequently used, and this both by the publican and the brewer.
Not only is the fact of the addition of water proved by the present analyses, but evidence of another character has been supplied by different parties to the Committee above referred to, showing the same fact. In particular, it has been proved that a publican could not afford to sell porter at the price which he pays for it, in the state in which it is supplied to him by the brewers, and realise a profit upon it, unless he had recourse to adulteration."
"Food and its adulterations" by Arthur Hill Hassall, 1855, pages xxvii - xxviii
The last sentence is striking. The price of Porter in a pub was so low that it had to be adulterated if the landlord were to make a living. And could the widespread adulteration of Porter have started its slow decline into extinction?